Walking-tractor



A. D. COLE.

WALKING TRACTOR.

APPLICATION man 1AN.23.1911.

1,320,741. Q Patented Nov. 4, 1919.

4 SHEETS-SHEET 1.

El [1D Illlllllllllllllll ll H B) IIIIHHHHH llll ARTHUR D. COLE.

W vFH TOR EYS.

A. D. COLE.

WALKING TRACTOR.

-APPL|CATION FILED JAN.23. 1911.

1,329,741 Patented Nov. 4, 1919.

4 SHEETSSHEET 3.

ATTORN EYS Patented Nov. 4, 1919.

4 SHEETS-SHEET 4.

INVENTOR:

RRT'HUR D. COLE.

LQ GZML HTTORN EYS.

ARTHUR 1). corn, or sr. PAUL, MINNESOTA.

' WALKING-TRACTOR.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Applicationfiled January 23, 1917. Serial No. 144,012.

To all whom it W W concern:

Be it known that I, ARTHUR D. Conn, a citizen of the United States, resident of St. Paul, county of Ramsey, State of Minnesota, have invented certain new and useful Improvements in alking-Tractors, of which the following is a specification.

The object of my invention is to provide a machine of the traction type in which 1 dispense with the usual traction Wheels.

A further object is to provide a walking tractor having shoes mounted for a uniform speed of travel, whereby any jerk or unevenness in the travel of the machine is avoided.

A further object is to provide a machine having a large traction surface in contact with the ground while the machine is in operation.

A still further object is to provide a machine of comparatively simple construction and one which will be strong and durable.

Other objects of the invention will appear from the following detailed description.

The invention consists generally in various constructions and combinations, all as hereinafter described and particularly pointed out in the claims.

Inthe accompanying drawings forming part of this specification,

Figure 1 is a plan view of a walking tractor embodying my invention,

Fig. 2 is a rear elevation of the same,

Fig. 3 is a longitudinal section of the machine,

Fig. 4 is a detail sectional view, showing the manner of operating the legs of the shoes from the source of power on the machine.

In the drawing, 2 represents theside rails of the frame andS the front .rail and 4 the rear rail, made preferably .of channelbar material on account of its strength and rigidity. 5 is a platform, mounted on the rear portion of the frame and on each side of this platform I prefer to provide rails 6 parallel with the rails 2 and-spaced therefrom and connecting the rail 3 at the front of the frame with the rail 4: at the rear endthereof. 7 is an engine of suitable type, preferably internal combustion, mounted between the rails 6. This engine has a fly wheel "8 and clutch 9 controlled by a lever 10. A gear 11 is controlled by a lever 12 that is mounted to mesh with the gear 13 of :a differential on the driving shaft 14:, which has bearings at centrically mounted on the ends of the shaft 14: and mesh with elliptic gears 16 which are mounted on triple crank shafts 17 journaled in the rails 2 and 6 on each side of the machine. Each of the cranks of the triple shafts has a connecting bar 18 pivoted thereon at one end and at its other end pivotally connected with an oscillating arm 19 journaled on a shaft 20 and having anti-friction,

bearing wheels 21 in guides 22 at the rear of the machine. When these bars 18 are gyrated, by the movement of the crank shafts, the arms 19 will oscillate on the centers 20 and move forward and backward in vertical planes.

Above the machine frame and supported by standards 22 and 23 is a rod 24 extending entirely across the machine. A series of legs 25 are provided upon each side of the machine and have longitudinal slots 26 therein at their upper ends to receive the rod 24 to allow vertical movement of the legs on said rods. Suitable collars 27 are mounted on said rod between the legs to hold their upper ends apart and guide the legs thereon. The lower portions of the legs 25 are pivotally connected at 28 with the corresponding connecting bars 18, there being one bar for each leg on each side of the machine and forward and backward movement of these bars will impart a corresponding oscillation to the legs, lifting them up and swinging their lower ends forward in much the same manner as the legs of a person are moved in walking.

There are preferably three legs on each side of the machine, but a greater or less number may be employed, if preferred, and the machine may also be adapted for use with one set of legs mounted substantially in the middle .portion thereof. I do. not wish to be confined, therefore, to the location of the legs or the number herein shown.

At the lower end of each leg I provid a shoe 29 pivotally attached at its middle portion to the end of the leg and having'a pivotal connection through a rod 30 'with its respective connecting bar. A sprlng 31 1s mounted on each rod for normally holding the shoe in a horizontal position but permitting it to yield and adapt itself to the surface of the ground over which the machine may be moving. When the bars 18 are gyrated by the movement of the crank shafts, the arms 19 will oscillate on the centers 29 and cause the shoes '29 to move 111.

straight, true, horizontal planes when in contact with the ground, and be lifted well up from the ground as they are carried over to a new position thereon. As indicated in v Fig. 4c, the elliptic gears are mounted and so timed with respect tov the eccentric driving gears that while the latter are on th low points of their peripheries or the point nearest the center, the elliptic gears will be on the high points and the slowing down of gear 16 and crank shaft 17 will compensate for the otherwise faster travel of the bar 18 while the crank shaft 17 is passing the lower dead center. In other words, instead of the arm 18 traveling faster as it approaches the vertical centers of the elliptic gear and slowing down "as it approaches the horizontal centers, the relative arrangement of the elliptic-gear and the eccentric driving gears causes a comparatively uniform travel of the bar 18-throughout its stroke and therefore eliminates any jerk or unevenness in the travel of the machine. I

Another pomt of lmportance 1n this ma' chine 1s the manner of mounting the arms 18 so that while the forward ends thereof are swinging downwardly on the arc of a circle, the rear ends are moving correspondingly in the opposite direction. The result is the shoes will move in horizontal planes while onthe ground instead of raising or tilting the machine frame, as usual in walking tractors of this type. The elliptic gears and the eccentric'gears are preferably in the ratio of 3 to '1,one revolution of an elliptic gear to three of the eccentric gear. The number of teeth may, however, be varied so longas the relative number of teeth re mains unchanged. The anti-friction wheels bearing on the walls of the guides serve to .take up lateral pressure or thrust, particularly when themachine is working on a side hill. Y

The tread surfaces of the shoes are preferably provided with corrugations 32 to increase their traction. These shoes have comparatively long traction surfaces for engagement with the ground and will positively prevent'the machine from slipping and will also adapt it for passing over ground where difficulty would be experienced I with a tractor of' the ordinary wheeled type. I I I The movement of the legs and bars is so timed that some of the traction shoes will be in contact with the ground all the time and the connecting bars being operated at the same speed, or substantiallyso, throughout their movement, the stroke of the legs will be uniform and the movement of the machine will be smooth and regular and all jerking or unevenness in the travel of the tractor usually incidental to machines of this type will be entirely avoided.

I have shown shafts having triple cranks for operating a corresponding number of connecting bars, but the number of cranks employed may be varied and I do not wish to be confined to the number or arrangement herein shown. 1

At the forward portion of the nachine are carrying and guiding wheels 33 mounted on an axle 3a to oscillate in a hanger 35. A steering post 36 has the usual worm and gear wheel connection with a spindle 37 which has bearings in the hanger 35.

In various ways the details of construction herein shown and described may be modified and still be within the scope of my invention.

I claim as my invention:

1. The combination, with a frame, and a source of motive power mounted thereon, of

legs mounted to oscillate in a vertical plane 'on a pivot common to all of said legs, bars pivotally connected with said legs respectively, a gear mechanism for driving said bars at a uniform rate of speed from said source of power, and traction shoes mounted on the lower ends of said legs and lifting upwardly and forwardly through the oscillation of said legs.

2. The combination, with a frame and a source of motive power mounted thereon, of a plurality of connecting bars geared to said source of motive power for a gyrating movement in a Vertical plane, suitable guides for said bars,' oscillating legs having traction shoes connected with said bars, the upper ends of said legs having slots therein and a rod mounted in said frame and having a sliding pivotal connection with said legs through said slots, for the purpose specified.

3.. The combination, with a frame and a source of motive power thereon, of a plurality of connecting bars upon opposite sides of said frame, an elliptical gear mechanism for connecting said bars with said source of motive power to impart a uniform continuous movement'to said bars, and oscillating legs having traction shoes connected with said bars.

4. The combination, with a'frame and a source of'motive power, of a plurality of connecting bars upon each sideof said gyrating them in a vertical plane, and legs having traction shoes connected with said bars.

' 5. The combination, w1th a frame and a source of motive power thereon, of connecting bars geared to said source of motive power, oscillating arms having a common pivot on said frame and pivotally connected respectively with said. bars, guides for said arms, and legs having traction shoes pivotally connected with said bars.

6. The combination, with a frame and a source of motive power thereon, of connecting bars geared to said source of motive power, oscillating arms having a common pivot on said frame and pivotally connected respectively with one end of said bars, guides for said arms, legs having traction shoes and rods yieldingly connecting said shoes with said bars for movement in a substantially horizontal plane while in contact with the ground.

7 In a walking tractor, the combination, with a plurality of connecting bars, of legs pivotally mounted thereon, traction shoes pivoted on said legs, a gearing for gyrating said bars, said gearing including means for operating said bars to impart a movement to said shoes in a substantially horizontal plane while in contact with the ground.

8. A walking tractor comprising a frame, a plurality of connecting bars, means affording a link connection between one end of said bars and said frame, a plurality of legs having a pivotal connection with said frame and pivoted on said bars respectively, traction shoes carried by said legs and a gearing connected with said bars for imparting a substantially uniform travel thereto throughout their stroke.

9. In a walking tractor, connecting bars,

Zopies of this patent may be obtained for legs pivoted thereon, shoes carried by said legs, crank shafts whereon said connecting bars are journaled at one end and on one side of said legs and curved guides for said bars on, the opposite side of said legs.

10. In a walking tractor, connecting bars, legs pivoted thereon, shoes carried by said legs, crank shafts whereon said connecting bars are journaled at one end and on one side of said legs and curved guides for said bars on the opposite side of said legs, said guides having anti-friction means for resisting lateral thrust of said bars.

11. The combination, with a frame and a source of motive power thereon, of legs mounted to oscillate in vertical planes, traction shoes mounted on said legs and lifting upwardly and forwardly through the oscillation of said legs, an elliptical gear and mechanism connecting said elliptical gear with said source of motive power and with said legs.

12. The combination, with a frame and a source of motive power thereon, of a plurality of connecting bars, an elliptical gear mechanism connecting said bars with said source of motive power to impart a uniform continuous movement to said bars, and oscillating legs having traction shoes connected with said bars.

In witness whereof, I have hereunto set my hand this 16th day of January 1917.

ARTHUR D. COLE.

five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

